The present invention relates to an arrangement at a cellular mobile telephone apparatus, comprising a protective hatch or flip pivotably arranged on a housing of said apparatus, said flip being pivotable around an axis and arranged at option to physically cover at least parts of a front surface on said apparatus, said axle comprises at least one active hinge means arranged in a cavity each, at the end of said housing, of which at least one of said hinge means is aimed to positively urge said flip to take a certain predetermined open position, when released.
Mobile telephones provided with such a flip or a hatch, have for covering a key pad on such telephones been used by most manufacturers for some years. The main purpose with such a flipxe2x80x94being to protect parts of a front surface of such a telephone, most often said keypad, and in that case protecting it from inadvertent manipulationxe2x80x94has by other manufacturers been tackled electronically through the use of key pad locks, being activated/deactivated by inserting a certain code for disabling/enabling the keypad.
Mobile telephones have by now become so small that it is almost a must to use such a flip for establishing the right distance between the earpiece and a sound receiving means, namely a sound channel leading to a microphone or the microphone itself. For obtaining the best possible fidelity of the sound registered by said microphone, it should preferably be placed in said flip.
It is for practical reasons desired that the flip on such a small mobile telephone should be made positively openable by for instance pressing a button on the side of the mobile telephone and that thereafter the flip be kept in a certain angular use-position. For geometrical reasons this can not be achieved by a conventional cam follower mechanism in the hinge means, frequently used until now.
Neither can such cam followers both establish the positions of the flip mentioned above and achieve an override function. An override function is a function enabling the flip in its open position to be turned beyond its speaking or use position, being about 160xc2x0 separated from the closed position, up to maybe 180xc2x0, when e.g. laid upside down on a table and pushed down unintentionally.
It is furthermore undesirable to have a design that results in residue axial stress on ears of the housing or the flip of such a telephone, which is the case when a cam-follower mechanism is used and which in the long run may cause endurance failures. Consequently other solutions (often more complicated than previous ones for obtaining almost the same functionality), like the one according to U.S. Pat. No. 5,649,309, for achieving the same function has seen the light of day. According to said patent an axle for a flip has two active hinges, the first one for keeping said flip in a closed position during pre-stressing of a spring in the second active hinge to a predetermined extent, and the second one supposed to after release of the urge from the first active hinge, pivot the flip into a predetermined potential speaking position, in which it is yieldably held by the first active hinge. The complexity of this and other solutions has given rise to inventive activity with the aim of achieving a somewhat simpler, implicitly thereby also more cost effective solution, which due to its simplicity also is better suited for automatic assembly.
It is therefore an object of the present invention to provide a mobile telephone apparatus with improved means for positively opening such a flip.
To meet this object said active hinge means comprise a shaft arrangement, colinear with said axis, comprising at least one unit built from an end piece and an elongated core fixedly connected thereto, around which core a torsion spring is arranged, said spring having at its respective ends fingers as counteracting parts for acting against a limit stop ridge in the housing, for allowing said spring to reach-an equilibrium position corresponding to an open flip (2) at 120-170xc2x0 from said closed position.
By this arrangement no axial force is exerted by said spring, which is enclosed in the arrangement and will therefore not affect the flip in any undesired way and will consequently only urge the flip towards an open use position. This gives the advantage that it eliminates the risk for fatigue cracking of the outer parts of the flip due to a constant tension from said spring. In the inverted case, in which ears for the hinge function are arranged only on the housing, the same goes for these ears.
Another object with the present invention is to simultaneously achieve an override function, i.e. a function that with the flip in an open position makes it possible to over-pivot, which for example takes care of the situation when the telephone is laid upside down and pressed upon without destroying essential parts, as also mentioned above.
According to an embodiment of the invention an end piece and a core together surrounds the torsional spring, giving the advantage that either one or the other ear of the spring is fixed while the other is pivoted under the indirect influence of said flip.
Almost unexpectectedly an override function of a most simple construction is achieved by letting one of the fingers of said spring be actuated by the flip when overridden, thus affecting said equilibrium position of the spring.